WO2015078691A2

WO2015078691A2 - Electrical machine, in particular electrical motor, and method for braking an electrical machine

Info

Publication number: WO2015078691A2
Application number: PCT/EP2014/074335
Authority: WO
Inventors: Dirk Diehl; Gunter Freitag
Original assignee: Siemens Aktiengesellschaft
Priority date: 2013-11-26
Filing date: 2014-11-12
Publication date: 2015-06-04
Also published as: WO2015078691A3; DE102013224149A1

Abstract

The invention relates, inter alia, to an electrical machine (10, 100a, 400), in particular an electrical motor (10, 100a, 400), in particular for a wheel hub drive, containing: an annular stator carrier (12), an annular rotor carrier (14), which has an inside diameter (D1) which is greater than an outside diameter (D2) of the stator carrier (12) and which is arranged concentrically or coaxially to the stator carrier (12) on a rotation axis (A), and a multi-plate brake (16) arranged on the stator carrier (12) and on the rotor carrier (14), wherein a first number of brake plates (70 to 76) of the multi-plate brake (16) is arranged on a receptacle part (21) of the stator carrier (12), and wherein the receptacle part (21) is integrally designed with the stator carrier (12).

Description

description

Electric machine, in particular electric motor, and method for braking an electric machine

The invention relates to an electric machine, in particular to an electric motor, which is suitable in particular as a wheel hub drive, for example. For an electric vehicle or for a hybrid vehicle with an electric drive and a conventional combustion drive. But other applications of the electric machine are possible, as will be explained in more detail below.

The invention relates to an electric machine, in particular an electric motor, in particular for a wheel hub drive, comprising:

an annular stator carrier,

a ring-shaped rotor carrier having an inner diameter which is larger than an outer diameter of the stator carrier and which is arranged on an axis of rotation concentrically or coaxially with the stator carrier, and

a lamellar brake arranged on the stator carrier and on the rotor carrier,

wherein a first number of brake disks of the multi-disk brake is arranged on a receiving part of the stator carrier, and wherein the receiving part is formed integrally with the stator carrier.

The invention also relates to a method for braking an electric machine or an electric motor, in particular the above-mentioned electric motor, comprising:

Arranging a multi-disc brake on a stator carrier and a rotor carrier of an electric machine,

Arranging an actuating element of the multi-disc brake on at least one lamella of the multi-disc brake,

Sealing the multi-disc brake with at least one gasket or exactly with a gasket, - Fill the multi-disc brake with a liquid, in particular permanently, and

- Actuation of the multi-disc brake for braking the electric machine, in particular several times.

It is an object of further developments of the invention to provide a compact composite of electric machine and brake, which is particularly well sealed against the ingress of dirt, dust, water, etc. In addition, an associated method for braking and possibly also for sealing a

Electric machine can be specified.

This object is achieved for an electric machine or for an electric motor by the electric machine or the electric motor according to claim 1 and for a method by the method specified in the independent claim. Further developments are specified in the subclaims.

The electric machine, in particular the electric motor, in particular the electric motor for a wheel hub drive, may contain:

an annular stator carrier,

an annular rotor carrier having an inner diameter which is larger than an outer diameter of the stator carrier and which is arranged on an axis of rotation concentrically or coaxially with the stator carrier, and

a lamellar brake arranged on the stator carrier and on the rotor carrier,

wherein a first number of brake disks of the multi-disc brake is arranged on a receiving part of the stator carrier, and wherein preferably the receiving part is formed integrally with the stator carrier.

The electric motor may be a traction engine of a vehicle. However, the electric motor can also be used in a motor mode and in a generator mode. Other applications are given below. In place of the electric motor and a generator can be used with the same features, eg. A generator (eg direct drive) for wind turbines, especially for wind turbines with a mast height greater than 50 meters or greater than 100 meters. A second number of brake disks of the multiple disk brake can be arranged on the rotor carrier. For example, 3 to 10 pairs of lamellae can be used. The lamellae may have an extent in the radial direction in the range of 2 centimeters to 10 centimeters.

On the rotor carrier can e.g. Be arranged permanent magnets. Alternatively, a magnetic field can be generated on the rotor in another way. Windings may be placed around soft magnetic laminations on the stator support, e.g. Dynamo sheet. The iron has, for example, a non-linear magnetization characteristic with saturation characteristic. The generation of high flux densities is possible in a simple way with the aid of soft magnetic iron with comparatively moderate currents. The sheets may be insulated from each other to prevent electrical eddy currents and associated losses.

An air gap may lie between the stator carrier and the rotor carrier, in which the high current through which the current-carrying conductor of the stator has a high magnetization prevails due to the high magnetic field present in the air gap. An air gap torque on the rotor is generated because this magnetic field acts on the permanent magnets of the rotor. Alternatively, however, other types of motors can be realized, for example. Asynchronous motor in which the rotor magnetic field is generated by induction in rods or windings of the rotor, DC machine, for example. With slip rings and / or so-called brushes, reluctance motor, permanent magnet machine with high

Reluctance component, etc.

The annular design of the rotor carrier or rotor and the stator carrier or stator allows a small weight, so that in a vehicle, the unsprung mass is as small as possible, resulting in good handling characteristics.

The receiving part may be arranged parallel to the axis of rotation adjacent to the stator. Thus, both the

Stator carrier and the multi-disc brake in the radial direction as far outside as possible to generate the largest possible drive torque or braking torque. The receiving part can have a greater extent in the radial direction than the stator carrier or a main part of the stator carrier, in particular an extension which is at least twice as large or which is at least three times as large as the extent of the stator carrier in the radial direction. Thus, braking forces can be better absorbed by the stator.

At least one support element may be arranged between the receiving part and an inner ring of the electric motor, in particular one side wall or a plurality of support struts. The at least one support element can be arranged obliquely to the axis of rotation. The smaller angle between support element (e.g., inside or outside and axis of rotation) is, for example, in the range of 45 degrees to 80 degrees. This creates a cavity that is suitable for receiving wishbones or wheel carriers.

The inner ring may also be arranged concentrically to the axis of rotation. Statorträger, support member and inner ring may be integrally formed, for example. As a casting.

The at least one support element may be a first support element. At least one second support element may be provided, in particular a second support wall or a plurality of second support struts, which may be arranged between the stator carrier and the inner ring.

A first distance in the axial direction between the at least one first support element and the at least one second support element The support element may be at least twice as large at a first radius as a second distance between these parts at a second radius lying further inwardly than the first radius.

The second support member may also serve to receive forces and the supports of the stator. Both support elements, the inner ring and the stator can form a housing, in particular a closed housing and / or an integrally formed housing. In the housing, the control electronics, in particular the power electronics of the engine or the machine can be arranged. The control electronics can, for example, be accessible or exchanged via one or more removable openings. For example. For example, the liquid cooling provided for the electric machine can also be used for the control electronics.

In the interior of the inner ring can be arranged at least one bearing for rotatably supporting the rotor carrier on the stator. For example, a skewed double cone bearing can be used or other double bearings. Alternatively, however, it is also possible to use a simple groove bearing whose rolling bodies are, for example, balls, rollers or cones. The multi-disc brake may be a wet brake, wherein the Lammellenbremse may preferably be arranged in an oil-filled space. The space can be completed by an outer side of the electric motor through a sealing element, in particular by a shaft seal. Due to the sealing element, the entry of fine dust by the brake into the environment can be prevented. Furthermore, it can be achieved that no corrosion of the brake occurs, in particular even if the multi-disc brake is rarely used, for example. Because mainly on recuperation, i. the generator's operation of the electric motor is braked.

In one embodiment, the oil can be a temperature resistance up to, for example, 300 degrees Celsius or 250 degrees Celsius or to have 200 degrees Celsius. This temperature can be matched to the temperature resistance of possibly present on the stator magnets. The oil should generate the lowest possible coefficients of friction. So thin oils can be used, which lead to low Schleppmomenten and allow easy tearing off of the oil film. Additives can be added to the oil to promote these properties.

The encapsulated multi-disc brake can be designed as a so-called life-time brake, in particular if it is used, for example, only occasionally to the generator brake of the electric machine. That Normally, no maintenance is incurred over the entire service life of the vehicle or another machine, possibly only one or more oil changes. The service life can be, for example, at least 10 years.

In one embodiment, a coating may be used which, for example, is also tuned to the temperatures mentioned for the oil and / or to the oil. The covering can be fixed on one side or on both sides to the inner plates and / or the outer plates. The slats can be made of steel. The coating may be based on plastic, for example. With additional particles that increase the friction. The inner disks may, for example, be made thinner than the outer disks, wherein, for example, only the inner disks may be coated on one or both sides with brake linings.

The oil-filled space can be a between the

Statorträger and the rotor arm lying air gap be sealed off with another seal, wherein in the air gap, the torque of the rotor is generated. The further seal preferably has a larger diameter than the sealing element, which seals to the outside. Alternatively, both seals may have the same diameter, in particular a diameter that is at least 10 percent or at least 20 percent smaller than the outside diameter of the stator carrier, in particular at the air gap of the stator

Electric motor. In one embodiment, however, can be built without a second sealing element. In this case, there is oil in the air gap and possibly reaches even into the bearing of the rotor or rotor carrier.

In another embodiment, the further seal has a larger diameter than the first seal. As a result, at least one of the seals can reduce the frictional forces that occur during rotation.

For the design of the seals, reference is made to the Freudenberg Simrit catalog below. A vehicle wheel can be driven directly by the electric motor, in particular without the use of a transmission. The vehicle wheel or a tire of the vehicle wheel is adjacent to a roadway and serves to propel the vehicle. By using the specified wheel hub motor, a simple construction of the vehicle can be achieved. The electronic control of the wheel hub motor can take place via inverter or inverter.

Alternatively, however, be provided in one embodiment, a transmission between the electric motor and the wheel or tire. The transmission can be arranged in the power flow direction when driving behind the multi-disc brake. Thus, the transmission can increase the braking torque. An actuator of the disc brake may include a ball ramp actuator or at least one hydraulic piston. The Kugelrampenaktuator or the piston can act directly on the slats. The actuating element can be arranged on the stator.

A Kugelrampenaktuator can take up a small space in the axial direction. The ball ramp actuator may include two rings. At least one of the two rings may have a ne slope be arranged. For example, balls or other rolling elements are mounted in corresponding grooves between the rings. The two rings are rotated to one another for actuation of the brake, whereby a gap between the rings is created or an existing gap is increased, resulting in the compression of the slats. For example. Only one ring is moved when pressed.

The ball ramp actuator itself may in turn be actuated by a hydraulic piston or in some other way, i. twisting each other the rings.

The electric motor can be connected to a rim, which in turn is connected to the rotor carrier and which contains a side wall or side struts which lead to a rim disk. The rim serves to receive a tire, in particular an air-filled tire. Alternatively, the tire or an "outside rim" can also be mounted directly on the periphery or circumference of the rotor carrier.

The rated power of the electric machine, in particular of the electric motor, may be less than 150 kilowatts. Alternatively, the rated power of the electric machine, in particular of the electric motor, also be greater than 150 kilowatts. The rated power is the relevant parameter for the design of the electric motor or the electric machine and is usually indicated on a nameplate of the electric machine.

Rated powers of less than 150 kilowatts can be used, for example, for passenger vehicles that are approved for less than 7 or 6 persons. Nominal outputs greater than 150 kilowatts or greater than 200 kilowatts can be used for heavy-duty vehicles, such as mining, agriculture, etc., especially for mining trucks, tractors, tractors.

However, both mentioned ranges of rated power can also be relevant for the winches of cranes or elevators. The two areas mentioned are also relevant for the generators of wind turbines.

The electric motor can be used for the wheel hub drive of a passenger transport vehicle, in particular for a vehicle that is approved for less than 7 or for less than 6 people. The advantages achieved by the very good sealing and the small installation space can speak in favor of using the electric motor in this area.

The stator can have an inside diameter in the range of 30 to 50 centimeters. The outside diameter of the

Statorträgers may preferably be at most by 2 centimeters, at most by three centimeters or at most by 6 centimeters larger than the inner diameter of the stator. These dimensions may result in a low weight of the electric motor, which in turn leads by low unsprung masses to good driving characteristics of a vehicle. Depending on the diameter, the design of the electric motor and the multi-disc brake is also carried out.

A method for braking an electric machine, in particular an electric motor, in particular an electric motor according to one of the preceding explanations, may include:

Arranging a multi-disc brake on a stator carrier and on a rotor carrier of an electric machine,

Arranging an actuating element of the multi-disc brake on the lamellae of the multi-disc brake,

Sealing the multi-disc brake with at least one gasket or exactly with a gasket,

- Fill the multi-disc brake with a liquid, in particular permanently, and

- Actuate the multi-disc brake to brake the electric machine.

With regard to the filling, it can apply that the brake is permanently or permanently filled with oil in order, for example, to have short response times. times, for example, less than 50 or less than 10 milliseconds. However, only temporary charging can be considered in certain applications, for example. Multi-stage torque converter or retarder, especially on trucks (trucks) and the like large vehicles, where it does not matter in milliseconds when braking. If the oil is not in the multi-disc brake, so-called drag losses can be reduced, for example. More specifically, during braking, the rotation of the rotor of an electric machine is braked and thus, for example, also a vehicle driven by the electric machine. The liquid can be a machine oil, see the explanations above. When operating the multi-disc brake, the electric motor can simultaneously operate in generator mode to increase the braking power. Alternatively, however, an operation of the multi-disc brake in engine operation or without generator operation is possible.

There may be separate cooling circuits for the multi-disc brake and for the stator windings. As cooling for the

Stator windings can be used a water jacket cooling.

Alternatively, a common cooling circuit for the multi-disc brake and for the stator windings may be used, especially if oil is also allowed in the air gap of the electric motor.

In other words, in addition to general electric machines u.a. a wheel hub drive with perimeter multi-disc brake specified. Wheel hub motors as a direct drive require a design larger seal than normal electrical drives. Especially the execution of the

Hub motor as external rotor has a design-related large diameter of the seal result. The external rotor has the advantage that the diameter of the rim best possible can be exploited to generate the torque. In addition, wheel hub motors are exposed to water and similar media due to their position in the wheel. They should be impermeable and at the same time withstand high injection pressures. This means that the seal must seal very well at high speeds and at standstill. The problem of the seal is aggravated when, for example, air must be sealed against air and not, for example, in a transmission air against oil. The integration of the motor, the brake and the power electronics is difficult due to the limited installation space.

So far this is an open point in such drives. The company Protean solves the problem, for example, by allowing the flooding of your drive and sheds or seals the windings and electrical parts. However, for example, entering water could freeze and the ice could damage the engine. The practical proof that a wheel hub drive for high speeds, e.g. for the application in the passenger car (passenger car), is dense, there is not yet.

The Schäffler company, for example, installs a drum brake in one of its wheel hub drives, which, however, is not intended for continuous operation, but is intended only as a fallback solution. Michelin and other manufacturers do not drive the wheel directly, but transmit torque and power through a transmission. It proposes a wheel hub drive with an external rotor as a direct drive. As a brake, a multi-disc brake is used, which is designed as a perimeter brake. Perimeter brake means the brake is not connected to the wheel hub but to the rim, i. here on the outside running rotor of the drive. That the brake is preferably not as

Disc but executed as a ring. A multi-disc brake can run in oil, see eg Figures 1 to 3. The running in oil and cooled by this disk set is, for example, by two Completed seals. The disk pack is sealed by a seal to the outside and can be sealed by a second internal seal against the electric machine.

Due to this structural design, the diameter on which the seal is inserted to the outside space can be reduced because the brake comprises the engine or the machine, i. is arranged on its periphery. The reservoir filled with oil then lies above the gap to be sealed. For example, air is sealed against oil with two gaskets. In FIGS. 1 to 3, the outer seal has a reduced diameter. Alternatively, seals of the same diameter can be used. The inner seal has a larger diameter in the sketched embodiment.

In an alternative embodiment, the diameter of the inner seal can be reduced by, for example, positioning the actuator centrally in the disk pack or between the disks of the disk pack and at the same time pressing both disk pack halves or parts axially outwards against the enclosing rotating part.

Nevertheless, the sealing effect is easier in the proposed solutions, because here air is sealed against oil and because the harmful media must first penetrate through the oil.

For example, if a Kugelrampenaktuator used, so there is a small space in the axial direction.

The annular shape of the brake wishbones can be guided into the interior of the wheel dish.

Other technical effects are: - The multi-disc brake is located above the gap to be sealed. Between the engine compartment and the exterior there is an oil-filled reservoir.

- The annular housing for the multi-disc brake can reduce the diameter for the critical seal. Due to the smaller diameter, the web speed is reduced, for which the seal must be designed.

- If dirt enters the drive, it first enters the oil-filled space and can be filtered out again via an oil circuit. The heat generated during braking, briefly, e.g. over 100 kilowatts, can be dissipated via the oil and reused in the vehicle.

- The majority of the heat is not, for example, as in the standard friction brakes (disc brake, drum brake) delivered to the ambient air and is not lost.

- By executing the brake as a perimeter brake, the wheel hub drive can be mounted on different suspension concepts, because the wishbone can reach into the wheel. Thus, such a design for several axes (eg front and / or rear) and axle systems can be designed simultaneously.

- The larger diameter of the disk set compared to a compact close-coupled disk brake leads to greater web speeds, which with the same contact pressure and the same friction surface higher braking performance and braking torques can be achieved.

- Further, the larger disk pack diameter improves the cooling or cooling of the brake, since the rotor-side fins in addition to the oil cooling on a short path and a cooling heat dissipation to the outside air allow.

As materials for the seals common materials for gaskets in question, see, for example, Technical Handbook 2007, Freudenberg Simrit GmbH & Co. KG, pages 34 and 35. Eg. FKM, i. Fluoroelastomers, due to

Abrasion resistance, temperature resistance and / or oil resistance. If permanent magnets are used in the rotor, then the temperatures in the oil and thus also be less than about 200 degrees Celsius at the seal to ensure permanent magnetization of the permanent magnets. The design of the sealing lip, in particular the angle on the oil side or on the air side are described, for example, on page 25 of the mentioned catalog, ie 35 to 60 degrees on the oil side and 12 to 30 degrees on the air side. The tension spring rings of the seal (s) can be inside the

Oil bath are arranged and oriented in the direction of the slats of the multi-disc brake, see, for example, Figure 6 (page 21) and Figure 7 (page 22) of the catalog. Alternatively, it is also possible to use a seal or a plurality of seals with a pressure spring ring.

Alternatively, seals from other manufacturers may be used that have similar or different design criteria.

The multi-disc brake can be designed according to common design principles. For example, externally toothed, coating-free steel lamellae can be used in alternation with internally toothed lamellae coated on both sides. The pad may have a thickness known from paper and be processed according to a processing technique of paper, so that it is also referred to as a paper pad. The covering may be plastic-based and / or contain additional particles which, for example, are similar to the additional particles used in dry clutches. Alternatively, one-sided occupied inner fins can be used, in which case, for example, also on the outer fins a coating can be arranged.

The above-described characteristics, features, and advantages of this invention, as well as the manner in which they are achieved, will become clearer and more clearly understood in connection with the following description of the embodiments. If the term "may" is used in this application it is both the technical possibility and the actual technical implementation. If the term "about" is used in this application, this means that the exact value is also disclosed.

The figures are not drawn to scale, in particular, the aspect ratios of the elements can be chosen differently. In the following, embodiments of the invention will be explained with reference to the accompanying drawings. Show:

FIG. 1 shows an electromagnetic wheel hub drive as external rotor with perimeter multi-disc brake (sectional view, perspective),

FIG. 2 shows a sectional view of the wheel hub drive,

Figure a detail view of the wheel hub drive, Figure a wheel hub external rotor motor, and

Figure 5 shows a configuration of an electric motor with eg.

twelve windings.

FIG. 1 shows an electromagnetic wheel hub drive 8 with an external rotor electric motor 10 and with a perimeter disk brake 16 in a perspective view

Cut. The electric motor 10 includes an annular stator carrier 12 and an annular rotor carrier 14, wherein the stator carrier 12 has a smaller outer diameter compared to an inner diameter of the rotor carrier 14. Statorträger 12 and rotor support 14 are arranged coaxially or concentrically with each other on a rotation axis A. A radial direction R is also shown in FIG.

The stator carrier 12 carries stator windings 62, see FIG. 2, and the rotor carrier 14 carries magnets, in particular permanent magnets. Nete or permanent magnets, which are not shown.

On the stator support 12 and on the rotor support 14, a camshaft brake 16 is arranged, which serves to brake the electric motor 10. The structure of the multi-disc brake 16 will be explained in more detail below, in particular with reference to FIG.

A rim 18 is secured to the rotor carrier 14, e.g. screwed. The rim 18 is, for example, a commercially available 15 inches (1 inch equals 2.54 centimeters), 16 inches, 17 inches or other rim. However, special figs adapted to the electric motor 10 may also be used. On the rim 18, a tire 20 is mounted, for example. An air-filled tire or a solid tire.

An exemplary electronic control of the electric motor 10 is not shown, but will be explained in more detail below with reference to FIG.

The stator support 12 widens on one side to a receiving part 21 which receives the inner disks of the multi-disc brake 16 and an actuator of the multi-disc brake 16, see Kugelrampenaktuator 52. The receiving part 21 is connected to a side wall 22 which is executed in the embodiment truncated cone-shaped but also can have a different shape. Possibly. the side wall 22 can also be omitted. Within the truncated cone shell but outside the housing 66, see Figure 2, are not shown wheel carriers are arranged, e.g. a wishbone.

In the position of use of the wheel hub drive 8, the tire 20 rests with a part of its peripheral surface on a carriageway or on another surface. If the wheel hub drive 8 mounted on the right side of the vehicle, so is the truncated cone shell of the side wall 22 on the left side of the wheel hub drive 8. Is the wheel hub drive 8, mounted on the left side of the vehicle, so is the truncated cone shell of the side wall 22 on the right side of the wheel hub drive 8, that is directed back towards the vehicle.

The side wall 22 is radially inwardly adjacent to an inner ring 24, which is mounted concentrically to the axis A and has a diameter which is matched to a bearing 34, for supporting a rotor pin or rotor inner part 32. The diameter of the inner ring 24 is considerably smaller than the diameter of the stator support 12, e.g. smaller than half the diameter of the stator support 12. The bearing 34 is, for example, a double bearing, e.g. a skewed double ball bearing. Alternatively, a simple ball bearing or rolling bearing is used.

A flat, disc-shaped side wall 26, for example, lies opposite the side wall 22 and borders the stator carrier 12 radially on the outside. Radially inside, the side wall 26 adjoins the inner ring 24. The side wall 26 can also have a different shape, for example along the radial direction R wavy, for example, to increase the stability.

The stator 12, the receiving part 21 of the stator 12, the side wall 22, the inner ring 24 and the side wall 26 form an annular housing 66, in which, for example, the control electronics of the electric motor 10 is arranged. Furthermore, oil pumps and / or oil filters and / or oil lines and possibly other components can be arranged in the preferably closed housing 66.

A rotor wall 30 connects the rotor carrier 14 with the rotor pin or rotor inner part 32. The rotor wall 30 is, for example, designed as a flat disk. The rotor wall 30 is arranged parallel to and at a distance from the side wall 26. In the exemplary embodiment, the rotor wall 30 is also arranged parallel to and at a distance from a side wall 40 of the rim 18. The rim center 42 of the rim 18 is arranged parallel to the center of the rotor wall without a gap to this. In the figure 1, an outer seal 44 is also shown, which is mounted on an annular projection 46 which is formed on the outside of the receiving part 21. The outer seal 44 will be explained in more detail below with reference to FIG.

An inner seal 48 is arranged on a projection of the receiving part 21 in a U-shaped recess 50. In the exemplary embodiment, the inner seal 48 lies exactly at the air gap of the electric motor 10, see air gap 64 in FIG. 2.

Between the outer seal 44 and the inner seal 44 is the multi-disc brake 18 and its fins in a chamber 88, see Figure 3, which is filled with a suitable oil.

The ball ramp actuator 52 is constructed, for example, as explained in the introduction, i. two rings which are rotated relative to one another, wherein at least one ring has a slope or a ramp on which balls or other bodies can roll.

FIG. 2 shows a sectional view of the wheel hub drive 8. Good to see in particular is the housing 66, on the circumference of which a stator cooling jacket 60 is arranged on the stator carrier 12. For example. a water jacket cooling with countercurrent principle or another cooling is used. The cooling is used to cool Statorblechpaketen and windings 62, which lead to the air gap 64 of the electric motor 10. Cooling jacket 60 and stator laminations and windings 62 are shown only symbolically in Figure 2, ie the design details can also be chosen differently than shown. The air gap 64 between the magnets of the rotor and the stator laminations has, for example, a gap width between 0.5 millimeters and 5 millimeters. The width of the air gap is, for example, between 4 centimeters and 15 centimeters. The Length of the air gap corresponds to the length of the circumference along the stator lamination.

FIG. 2 also shows a distance AI and a distance A2 which lie at a radius R1 or R2 between the side walls 22 and 26. The radius R2 is smaller than the radius Rl. The distance A2 is smaller than the distance AI, for example by at least half the value of the distance AI. The values of the distances A 1 and A 2 are given by the shape of the side wall 22 widening as the radial distance from the axis A increases. The distance AI or A2 is measured, for example, from the inner surface of the side wall 26 to the inner surface of the side wall 22. Alternatively, other reference values can be selected, for example, a center line of the side wall 26 or 22, wherein, however, the above-mentioned relationships between the distances AI and A2 may also apply.

An inner diameter D 1 of the rotor carrier 14 is larger than an outer diameter D 2 of the stator carrier 12, for example by at least 10 percent of the inner diameter D 1. An inner diameter D 3 of the stator carrier 12 is smaller than the outer diameter D 2 of the stator carrier 12, for example a maximum of 10 percent of the outer diameter D2.

3 shows a detailed view of the wheel hub drive 8, in particular a detailed view of the receiving part 21, on the receiving part 21 are linear guides 95 formed, for example. Trapezoidal projections and trapezoidal recesses or grooves which extend in the axial direction A, ie parallel to the axis A. , Alternatively, for example, rectangular or square shapes or combination of said shapes are used. The linear guides 95 are tuned to internal teeth of inner plates 70 to 76 of the multi-disc brake 16. The inner disks 70 to 76 are formed as laminar rings, for example. Steel. The inner disks 70 to 76 are on the Li near guides 95 mounted axially movable and can be compressed by the below explained in more detail actuator of the multi-disc brake 16, in particular together with below explained in more detail outer plates 80 to 86 of the lamella brake 16.

The inner disks 70 to 76 are coated with a coating, not shown, in particular on both sides or on one side, see for another brake and the lining 370a in Figure 4. For the lining and the oil of the multi-disc brake 16, the statements mentioned in the introduction apply.

The free ends of the inner disks 70 to 86 opposite linear guides 96 are formed, for example, may also consist of trapezoidal projections and trapezoidal recesses, preferably in the axial direction a running. Alternatively, for example, rectangular or square shapes or combination of said shapes are used. The linear guides 96 are matched to external teeth of outer lamellae 80 to 86 of the multi-disc brake 16. The outer plates 80 to 86 are also formed as laminar rings, for example. Steel. The outer disks 80 to 86 are axially movably mounted on the linear guides 96 and can be compressed by the actuating element of the disk brake 16 explained in greater detail below, in particular indirectly via the inner disks 70 to 76 of the disk brake 16.

The outer plates 80 to 86 are not coated in the embodiment. Alternatively, both inner disks and outer disks can be coated, for example, in each case on the side or surface pointing outwards (above) or on the side or surface pointing inwards (downwards). Further alternatively, only the outer plates can be coated. Although four pairs of laminations are shown in FIG. 3, a different number of pairs may be used, in particular a number lying between two and twenty. An annular oil chamber 88 is formed between the linear guides 95 and 96. Due to the arranged in the oil chamber 88 inner disks 70 to 76 in alternation with the outer disks 80 to 84 results in the non-actuated state of the multi-disc brake 16, a meandering course of the oil in the oil chamber 16 between the mutually spaced lamellae. If the multi-disc brake 16 is actuated, the gaps between the fins 70 to 76, 80 to 86 are reduced until adjacent fins 70 to 76, 80 to 86 touch each other. The oil is thereby forced out of the meanders and can, for example, along the guides 95, 96 flow in the side region of the oil chamber 88, from where it flows back when relaxing or releasing the multi-disc brake 16, in particular along the meandering then again.

The oil chamber 88 may communicate with an oil filter and / or an oil pump via oil lines or oil passages (not shown) in the receiving part 21. The oil can, for example, be supplied to a cooling device and / or serve to heat the vehicle interior.

The actuator of the multi-disc brake 16 is formed in the embodiment by a Kugelrampenaktuator 52 which includes two groove rings 90, 92, which are arranged in the receiving part 21 in the vicinity of the inner plate 76 and the outer plate 86. Alternatively, the ball ramp actuator 52 may also abut an outer fin. The rings 90, 92 have an average diameter which corresponds approximately to the mean diameter of the inner disks 70 to 76 or, for example, deviates only by a maximum of 5 percent or by a maximum of 10 percent from the mean diameter of the inner disks 70 to 76. For determining the mean diameter of the inner disks 70 to 76, reference is made, for example, to a smallest inner diameter of the toothing and to the outer diameter of the relevant inner disk 70 to 76.

Balls, for example, see ball 54, or other rolling elements are arranged between the groove rings 90, 92. Im not actuated Condition, there may already be a gap 94 between the rings 90 and 92. Alternatively, the gap 94 is formed only when operating the multi-disc brake 16 by the rotation of the ring 92 relative to the ring 90. Alternatively, both rings 90, 92 are rotated when operating the multi-disc brake 16 or only the ring 90. The rotation takes place in the circumferential direction of the rings 90th or 92.

The ring 90 and / or the ring 92 has a pitch of the groove for receiving the balls, see e.g. Ball 54, or the other rolling elements. This pitch increases the spacing of the rings 90, 92 upon rotation of at least one ring 90, 92. The ball ramp actuator 52 may communicate with the oil chamber 88 to lubricate it. Alternatively, separate lubrication may be used for the ball ramp actuator 52.

The rotation of the rings 90, 92 to each other can be done by a known device, for example. Using a hydraulic or pneumatic piston.

An unillustrated return element facilitates the release of the multi-disc brake 16, for example, suitable spring washers between the fins 70 to 76 or 80 to 86. Alternatively, no separate return elements for the rear part of the multi-disc brake 16 are used.

A screw 97 can be used for attaching a stop ring 99, not shown, for the inner plates 70 to 76. Alternatively, a snap ring may be used, i. the screw 97 is not used.

A screw 98 can serve for fastening a stop ring (not shown) for the outer disks 80 to 86 on the rotor carrier 14 and a chamber wall 87 on the rotor carrier 14. Alternatively, a snap ring can be used as a stop ring here as a stop for the outer plates 80 to 86. Next alternatively, only one can be inside or outside Stop ring can be used. The chamber wall 87 is pulled as far inward as possible in order to reduce the diameter of the outer seal 44 and thereby minimize friction losses. Alternatively, the chamber wall 87 may be shortened, wherein the outer seal 44 may be located farther out, for example, at the same radius as the inner seal 48.

A width Bl of the receiving part 21 is, for example, more than twice or more than three times as large as a width B2 of the stator carrier 12.

The outer seal 44 is mounted on the projection 46. In the exemplary embodiment, a U-shaped shaft seal is used as the outer seal 44, which contains the following parts: an annular bearing part, which rests against a side surface of the projection 46 and contains, for example, a metal insert or consists of metal,

a transverse, in particular at an angle of 90 degrees, arranged to the bearing part disc-shaped central part, which, for example. Also contains metal or consists of metal, and

a ring-shaped free part arranged transversely to the middle part with a sealing lip, for example of a plastic material, possibly supported by a metal ring, in particular a compression spring ring.

The bearing part and the free part extend in the same direction away from the central part, which can also be referred to as a base. The base of the outer seal 44 is in the embodiment outside of an opening in which the outer seal 44 is mounted. Thus, the sealing lip exerts a radially outwardly directed pressure on the rotating during operation of the electric motor 10 side wall 87. Alternatively, it is also possible to use a V-shaped or an L-shaped outer seal 44, reference being made to the introduction for all the types of seal mentioned with regard to the choice of material and the temperature resistance. The inner seal 48 is mounted in the example. Annular recess 50. In the embodiment, a U-shaped shaft seal is used as the inner seal 48, which contains the following parts:

a ring-shaped bearing part, which bears against the bottom of the recess 50 and, for example, contains a metal insert or consists of metal,

a transverse, in particular at an angle of 90 degrees, arranged to the bearing part disc-shaped central part, which, for example, also contains metal or consists of metal and which bears against a side surface of the recess 50, and

a ring-shaped, free part arranged transversely to the middle part with a sealing lip, for example of a plastic material.

The bearing part and the free part extend in the same direction away from the central part, which can also be referred to as a base. In the exemplary embodiment, the base of the inner seal 48 lies against the side wall of the recess 50 which is closer to the air gap 64. The sealing lip thus exerts a radially outwardly directed pressure on the rotor carrier 14 rotating during operation of the electric motor 10. Alternatively, a V-shaped or an L-shaped inner seal 48 may be used, reference being made to the introduction with regard to the choice of material and the temperature resistance of all mentioned types of seals.

One or both seals 44, 48 may also be mounted on the rotor arm 14, e.g. B. with pressure spring rings in the seals. The position of the base remains unchanged, then the sealing lip of the seal 44 then on the receiving part 21 and the sealing lip of the seal 48 then also bear against the receiving part 21. In another embodiment, the Kugelrampenak- tuator 52 and 54 can be arranged centrally in the disk set of the multi-disc brake 16 or another multi-disc brake. Instead of a ball ramp actuator, a hydraulic Lischer double piston or more hydraulically operated pistons can be used. In both cases, the inner seal 48 can then be arranged further radially inward than shown in Figure 3, in particular on the same radius as the outer seal 44. The air gap 64 can remain in the same position, as shown in Figure 3, wherein However, there is a radial gap between the inner seal and the air gap 64. In another variant can be built without inner seal 48. In this case, the oil of the oil chamber 88 also penetrates into the air gap 64 and into the bearing 34, see FIGS. 1 and 2.

During assembly of the electric motor 10, the following occurs:

to the stator support 12, the cooling, the windings and the laminated cores are mounted,

- Then the seal 48, the ring 90, the balls 54, possibly with so-called cage, and the ring 92 used, the parts 90 to 92, if necessary, as a prefabricated component,

- Then the rotor carrier 14 is mounted,

- Then alternately the outer plates 80 to 86 and the inner plates 70 to 76 are inserted,

with the aid of the screw 97 and with other screws or in another way, the stop ring for the inner plates 70 to 76 is fastened, in particular for the outer outer plate 80,

the stop ring for the outer plates 80 to 86, in particular for the outer outer plate 80, is placed,

- The wall 87 and the stop ring for the outer plates is fastened with the screw 98 and with other screws,

- The seal 44 is used, and

- Equal or later, the oil chamber 88 is filled with oil. If the seal 48 is running in a groove, the rotor 14 may be split at that location, ie at the seal. In this way, the multi-disc brake 16 can be maintained even without disassembly of the rim 18 by performing the above steps after the oil drain in reverse order.

FIG. 4 shows a wheel hub external rotor motor 100a which is part of a wheel hub drive 102a. A rotor 120a rotates about the rotation axis A. The electric motor 100a includes a stator 140a disposed inside the rotor 120a.

The stator 140a includes a cylindrical ring which is closed on one side (here on the right) by an example. Circular side wall, which is possibly reinforced by radial ribs, so that forms a stator interior in the interior of the ring. The side wall is firmly connected to the side facing away from the stator interior side with a fixation 160a, which is for example. Bearing mounted on a vehicle frame, in particular using a transverse link. In the example, the sidewall of the stator 140a is on the right side. A rotor shaft is not available, but can be provided.

The rotor 120a also includes a cylindrical ring which is rotatably mounted about the rotation axis A. The cylindrical ring of the stator 140a and the cylindrical ring of the rotor 120a are coaxially supported with each other, with the ring of the rotor 120a being disposed outside the ring of the stator 14a. On the inside of the ring of the rotor 120a, permanent magnets M2 are disposed, which are driven by a rotating magnetic field generated by the coils of the stator 140a.

One side of the ring of the rotor 120a is closed by a circular disk. On the free side of the ring of the rotor 120a, on the right in FIG. 4, there is a rotor plate 150a, which, for example, is designed as a disk ring or circular ring and covers an engine interior of the engine 100a. The ring of the stator 140a has a smaller height in the axial direction than the ring of the rotor 120a, so that it can be arranged in the interior of the motor 100a. The rotor 120a is mounted on the stator 140a by means of a bearing 180a, for example by means of a deep groove ball bearing, which contains, for example, cones which are tensioned relative to one another. Thus, the rotor 120a can rotate around the rotation axis A and also around the stator 140a.

The rotor 120a and the stator 140a are shown shortened in the radial direction R in FIG. The motor 100a is completely within a rim 200a. The rim 200a is, for example, a 15, 16, 17, 18 or a 19 inch rim. Alternatively, the rim 200a may have a different nominal dimension. The rim 200a has on its left in Figure 4 page a rim support 210a, which is formed, for example. As a circular disc. Alternatively or additionally, the rim carrier 210a may include ribs.

On the rim 200a, a tire 220a is mounted, which contains, for example, a rubber compound and, for example, steel inserts.

A screw 240a and other screw not shown are used to attach the rotor plate

150a on the rotor 120a. A seal 260a may be provided between the rotor plate 150a and the rotor 120a along the circumferential direction, e.g. a static sealing o-ring or a static sealing gasket.

A screw 320a is used to attach the rim 200a or more precisely the rim support 210a on the rotor 120a. The rotor 120a has an outwardly facing side wall to which the screw joint 320a is attached. Further screw connections, not shown, are used to fasten the rim 200a to the rotor sidewall. Possibly. For fixing the rim 200a, a rotor shaft can again be formed on the rotor 120a, see FIGS. 1 to 3. Alternatively, another manner of fastening the tire 220a to the motor 100a may be selected, eg directly on the rotor 120a, ie without using an additional rim or using an "outer rim", ie, for example, without rim carrier 210a.

A multi-disc brake 360a is disposed on the rotor 360a and on the stator 140a. More specifically, internal lathes 70a are disposed on the stator 140a with internal teeth, and external lathes on the rotor are arranged on linear guides on the rotor. In the exemplary embodiment, there are two pairs of lamellae and an additional outer lamella 80a. Again, the inner blades 70a coated on both sides with a coating, see, for example, pad 370a on the left side of the right inner plate 70a. However, a different number of pairs of blades 70a, 80a may be used.

An actuator 340a (actuator) of the multi-disc brake 360a is disposed on the stator 140a. Seals of the multi-disc brake 360a are not shown in FIG. However, the same or similar sealing concepts as explained above with reference to FIGS. 1 to 3 can be used. The multi-disc brake 360a can also be arranged closer to the rotor side wall 120a, which also applies to the figures 1 to 3, i. between magnets, e.g. M2, or stator windings and the rotor side wall 120a.

It can be a U-ring again or it can have multiple U-rings or other sealing elements for sealing the multi-disc brake

360a, e.g. a V-ring. Also, one or more L-shaped seal member (s) may be used for sealing the multi-disc brake 360a or the mentioned modifications. Combinations of these types of seals are possible in all embodiments.

A stator with a cone-shaped side wall can also be used with the motor 100a. The assembly of the lamellar Brake 360a takes place, for example, like the assembly of the multi-disc brake 16.

FIG. 5 shows a configuration of an electric motor 400 with, for example, twelve windings W1 to W12. Alternatively, a different number of turns can be used.

The electric motor 400 is an external rotor motor and includes a stator 402 and a rotor 404. On the stator 402, the windings W1 to W12 are arranged around laminations. A plurality of magnets are arranged on the rotor, a magnet MIO being shown in FIG. Alternatively, electrically conductive rods or windings may be used on the rotor 404 into which currents are inductively induced to generate the magnetic fields.

The electric motor 400 also includes a perimeter multi-disc brake, which, however, is not shown in FIG. 4 for reasons of clarity. The electric motor 400 may be constructed like the electric motors 10 and 100a shown in FIGS.

The switching bridges associated with the windings W7 to W12 are, like the switching bridges assigned to the windings W1 to W6, driven in the opposite direction of winding of the windings W7 to W12 in comparison to the winding sense of the windings W1 to W6. With the same sense of winding / wiring, the windings W7 to W12 associated with switching bridges inversely to the windings Wl to W6 associated switching bridges are driven, inversely meaning that, for example, the drive signals for the upper bridge transistor / - switch and the drive signals for the lower Bridge tripping transistor / switch are reversed. The electric motor 400 corresponds, for example, to the electric motor 10, see FIGS. 1 to 3, or the wheel hub motor 100 a. In the configuration shown in FIG. 5, six phases can be used to drive twelve half-bridges. AI ternatively, only six half-bridges can be used, as explained in more detail below.

The windings W1 to W12 can be connected together at a neutral point. For the other ends of the windings W1 to W6, the following circuit is present:

- The winding Wl is connected to the center node of a first half-bridge, wherein the central node is connected to the working distances of both switching elements of the half-bridge, which also applies to the other half-bridges.

the winding W2 is connected to the middle node of a second half-bridge,

the winding W3 is connected to the middle node of a third half-bridge,

the winding W4 is connected to the middle node of a fourth half-bridge,

the winding W5 is connected to the middle node of a fifth half-bridge, and

- The winding W6 is connected to the center node of a sixth half-bridge.

The lower switching element of the six half-bridges is in each case connected to a common negative line. The top

The switching element of the six half-bridges is in each case connected to a common positive line.

Each of the six half bridges is controlled by a drive signal line pair, the one drive line being connected to a control terminal of the upper switching element, e.g. Gate, and the other drive line respectively leads to a control terminal of the lower switching element of the respective half-bridge.

In the configuration shown, the six phases are arranged zueinan with increasing phase shift between adjacent phases, ie, for example 0 angle degree, 60, 120, 180, 240, and 300 degrees of angle. Due to the use of six phases to drive twelve windings Wl to W12 results in a torque characteristic as a function of speed. The efficiency is also dependent on the speed. The half bridges belonging to the windings W6 to W12 are driven like the half bridges of the windings W1 to W6 based on the six phases. However, it can also be worked with only six half-bridges larger power when the first half-bridge, for example, the current through the windings Wl and W7, the second half-bridge the current through the windings W2 and W8, etc. controls.

For FIG. 5, Q = 12, p = 1 and m = 6, where Q is the number of slots used, p is the pole pair number and m is the number of electrical phases. Furthermore:

q = Q / (2p * m) = 1,

where q is the number of grooves used per winding.

Other values for Q, p and m are also possible. Also other winding schemes can be used.

Instead of external rotor motors / generators, internal rotors can also be equipped with wet-running multi-disc brakes. However, with internal rotor motors / generators, sealing is often easier due to the smaller radius at which the air gap is located, compared to an external rotor machine of the same rated power.

The embodiments are not to scale and are not restrictive. Modifications within the scope of expert action are possible. Although the invention has been further illustrated and described in detail by the preferred embodiment, the invention is not limited by the disclosed examples, and other variations can be derived therefrom by those skilled in the art without departing from the scope of the invention. The developments and refinements mentioned in the introduction can be combined with one another. The embodiments mentioned in the description of the figures can also be used with each other be combined. Furthermore, the developments and refinements mentioned in the introduction can be combined with the exemplary embodiments mentioned in the description of the figures.

Claims

claims

1. Electric machine (10, 100a, 400), in particular electric motor (10, 100a, 400), in particular for a wheel hub drive, comprising:

an annular stator support (12),

an annular rotor carrier (14) having an inner diameter (Dl) which is larger than an outer diameter (D2) of the stator (12) and which is arranged on a rotational axis (A) concentric or coaxial with the stator carrier (12) .

a disk brake (16) arranged on the stator carrier (12) and on the rotor carrier (14),

wherein a first number of brake disks (70 to 76) of the disk brake (16) is arranged on a receiving part (21) of the stator carrier (12),

and wherein preferably the receiving part (21) is formed integrally with the stator carrier (12).

2. Electric machine (10, 100a, 400) according to claim 1, wherein the receiving part (21) parallel to the axis of rotation (A) next to the stator (12) is arranged.

3. Electric machine (10, 100a, 400) according to claim 1 or 2, wherein the receiving part (21) in the radial direction (R) has a greater extent (Bl) than an extension (B2) of the stator (B2, 12) in the radial Direction (R), in particular an extent (Bl), which is at least twice as large or at least three times as large as the extension (B2) of the stator (12) in the radial direction (R).

4. Electric machine (10, 100a, 400) according to one of the preceding claims, wherein between the receiving part (21) and an inner ring (24) of the electric motor (10, 100a, 400) at least one support element (22) is arranged, in particular a side wall (22) or a plurality of support struts,

wherein preferably at least one support element (22) is arranged obliquely to the axis of rotation (A).

5. Electric machine (10, 100a, 400) according to claim 4, wherein the at least one support element (22) is a first support element (22),

and wherein at least one second support element (26), in particular a second support wall (26) or a plurality of second support struts, are arranged between the stator carrier (12) and the inner ring (24),

wherein preferably a first distance (AI) in the axial direction (A) between the at least one first support element (22) and the at least one second support element (26) at a first radius (Rl) is at least twice as large as a second distance (A2) between these parts (22, 26) at a second radius (R2), which is located further inside than the first radius (Rl).

6. Electric machine (10, 100a, 400) according to claim 4 or 5, wherein at least one bearing (34) for rotatably supporting the rotor carrier (14) on the stator (12) is arranged in the interior of the inner ring (24).

7. Electric machine (10, 100a, 400) according to one of the preceding claims, wherein the multi-disc brake (16) is a wet brake, wherein the Lammellenbremse (16) is preferably arranged in an oil-filled space (88),

wherein preferably the installation space (88) is closed towards an outer side of the electric machine (10, 100a, 400) by a sealing element (44), in particular by a shaft sealing ring (44).

8. Electric machine (10, 100a, 400) according to claim 7, wherein the oil-filled installation space (88) to a between the stator (12) and the rotor carrier (14) lying air gap (64) is sealed with a further seal (48) .

wherein the further seal (48) preferably has a larger diameter than the sealing element (44) which seals to the outside.

9. Electric machine (10, 100a, 400) according to one of the preceding claims, wherein a vehicle is driven directly by the electric motor (10, 100a, 400), in particular without the use of a transmission.

10. Electrical machine (10, 100 a, 400) according to any one of the preceding claims, wherein an actuating element (52) of the Lammellenbremse (16) includes a Kugelrampenaktuator (52, 54) or at least one hydraulic piston which directly on the lamellae (70 to 76 ),

and wherein preferably the actuating element (52, 54; 340a) is arranged on the stator carrier (12).

11. Electric motor (10, 100a, 400) according to one of the preceding claims, with a rim (18), with the rotor arm

(14) is connected and which includes a side wall (40) or side struts leading to a rim disk.

12. Electric machine (10, 100a, 400) according to one of the preceding claims, wherein the rated power of the electric machine

(10, 100a, 400) is less than 150 kilowatts or the rated power of the electric machine (10, 100a, 400) is greater than 150 kilowatts.

13. Electric machine (10, 100a, 400) according to any one of the preceding claims, wherein the electric motor (10, 100a, 400) is used for the wheel hub drive of a passenger transport vehicle, in particular for a vehicle that is for less than 7 or for less than 6 people is allowed.

14. Electric machine (10, 100a, 400) according to one of the preceding claims, wherein the stator (12) has an inner diameter (D3) in the range of 30 to 50 centimeters and wherein the outer diameter (D2) of the stator (12) preferably not more than 2 centimeters, not more than 3 centimeters or at most 6 centimeters larger than the inside diameter (D3).

15. A method for braking an electric machine (10, 100a, 400), in particular an electric motor (10, 100a, 400), in particular an electric motor (10, 100a, 400) according to one of the preceding claims, comprising:

Arranging a multi-disc brake (16, 360a) on one

Stator carrier (12) and on a rotor carrier (14) of an electric machine (10, 100a, 400),

Arranging an actuating element (52, 54; 340a) of the multi-disc brake (16) on at least one lamella (70 to 76) of the disc brake (16, 360a),

Sealing the multi-disc brake (13, 360a) with at least one seal (44, 48) or precisely with a seal (44),

Filling the multi-disc brake (13, 360a) with a fluid, in particular permanently,

Actuate the multi-disc brake (13, 360a) to brake the

Electric machine (10, 100a, 400).